/********************************************************************
 KWin - the KDE window manager
 This file is part of the KDE project.

Copyright (C) 2013 Martin Gräßlin <mgraesslin@kde.org>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
// own
#include "wayland_backend.h"
#include <config-kwin.h>
// KWin
#include "cursor.h"
#include "logging.h"
#include "main.h"
#include "scene_qpainter_wayland_backend.h"
#include "screens.h"
#include "wayland_server.h"
#include "wayland_cursor_theme.h"
#if HAVE_WAYLAND_EGL
#include "egl_wayland_backend.h"
#endif
#include <KWayland/Client/buffer.h>
#include <KWayland/Client/compositor.h>
#include <KWayland/Client/connection_thread.h>
#include <KWayland/Client/event_queue.h>
#include <KWayland/Client/keyboard.h>
#include <KWayland/Client/pointer.h>
#include <KWayland/Client/pointerconstraints.h>
#include <KWayland/Client/pointergestures.h>
#include <KWayland/Client/region.h>
#include <KWayland/Client/registry.h>
#include <KWayland/Client/seat.h>
#include <KWayland/Client/server_decoration.h>
#include <KWayland/Client/shell.h>
#include <KWayland/Client/shm_pool.h>
#include <KWayland/Client/surface.h>
#include <KWayland/Client/touch.h>
#include <KWayland/Client/xdgshell.h>
#include <KWayland/Server/buffer_interface.h>
#include <KWayland/Server/display.h>
#include <KWayland/Server/seat_interface.h>
#include <KWayland/Server/surface_interface.h>

#include <KLocalizedString>
// Qt
#include <QMetaMethod>
#include <QThread>
// Wayland
#include <wayland-cursor.h>

#include <linux/input.h>

namespace KWin
{
namespace Wayland
{

using namespace KWayland::Client;

WaylandSeat::WaylandSeat(wl_seat *seat, WaylandBackend *backend)
    : QObject(NULL)
    , m_seat(new Seat(this))
    , m_pointer(NULL)
    , m_keyboard(NULL)
    , m_touch(nullptr)
    , m_cursor(NULL)
    , m_enteredSerial(0)
    , m_backend(backend)
    , m_installCursor(false)
{
    m_seat->setup(seat);
    connect(m_seat, &Seat::hasKeyboardChanged, this,
        [this](bool hasKeyboard) {
            if (hasKeyboard) {
                m_keyboard = m_seat->createKeyboard(this);
                connect(m_keyboard, &Keyboard::keyChanged, this,
                    [this](quint32 key, Keyboard::KeyState state, quint32 time) {
                        switch (state) {
                        case Keyboard::KeyState::Pressed:
                            if (key == KEY_RIGHTCTRL) {
                                m_backend->togglePointerConfinement();
                            }
                            m_backend->keyboardKeyPressed(key, time);
                            break;
                        case Keyboard::KeyState::Released:
                            m_backend->keyboardKeyReleased(key, time);
                            break;
                        default:
                            Q_UNREACHABLE();
                        }
                    }
                );
                connect(m_keyboard, &Keyboard::modifiersChanged, this,
                    [this](quint32 depressed, quint32 latched, quint32 locked, quint32 group) {
                        m_backend->keyboardModifiers(depressed, latched, locked, group);
                    }
                );
                connect(m_keyboard, &Keyboard::keymapChanged, this,
                    [this](int fd, quint32 size) {
                        m_backend->keymapChange(fd, size);
                    }
                );
            } else {
                destroyKeyboard();
            }
        }
    );
    connect(m_seat, &Seat::hasPointerChanged, this,
        [this](bool hasPointer) {
            if (hasPointer && !m_pointer) {
                m_pointer = m_seat->createPointer(this);
                setupPointerGestures();
                connect(m_pointer, &Pointer::entered, this,
                    [this](quint32 serial) {
                        m_enteredSerial = serial;
                        if (!m_installCursor) {
                            // explicitly hide cursor
                            m_pointer->hideCursor();
                        }
                    }
                );
                connect(m_pointer, &Pointer::motion, this,
                    [this](const QPointF &relativeToSurface, quint32 time) {
                        m_backend->pointerMotion(relativeToSurface, time);
                    }
                );
                connect(m_pointer, &Pointer::buttonStateChanged, this,
                    [this](quint32 serial, quint32 time, quint32 button, Pointer::ButtonState state) {
                        Q_UNUSED(serial)
                        switch (state) {
                        case Pointer::ButtonState::Pressed:
                            m_backend->pointerButtonPressed(button, time);
                            break;
                        case Pointer::ButtonState::Released:
                            m_backend->pointerButtonReleased(button, time);
                            break;
                        default:
                            Q_UNREACHABLE();
                        }
                    }
                );
                connect(m_pointer, &Pointer::axisChanged, this,
                    [this](quint32 time, Pointer::Axis axis, qreal delta) {
                        switch (axis) {
                        case Pointer::Axis::Horizontal:
                            m_backend->pointerAxisHorizontal(delta, time);
                            break;
                        case Pointer::Axis::Vertical:
                            m_backend->pointerAxisVertical(delta, time);
                            break;
                        default:
                            Q_UNREACHABLE();
                        }
                    }
                );
            } else {
                destroyPointer();
            }
        }
    );
    connect(m_seat, &Seat::hasTouchChanged,
        [this] (bool hasTouch) {
            if (hasTouch && !m_touch) {
                m_touch = m_seat->createTouch(this);
                connect(m_touch, &Touch::sequenceCanceled, m_backend, &Platform::touchCancel);
                connect(m_touch, &Touch::frameEnded, m_backend, &Platform::touchFrame);
                connect(m_touch, &Touch::sequenceStarted, this,
                    [this] (TouchPoint *tp) {
                        m_backend->touchDown(tp->id(), tp->position(), tp->time());
                    }
                );
                connect(m_touch, &Touch::pointAdded, this,
                    [this] (TouchPoint *tp) {
                        m_backend->touchDown(tp->id(), tp->position(), tp->time());
                    }
                );
                connect(m_touch, &Touch::pointRemoved, this,
                    [this] (TouchPoint *tp) {
                        m_backend->touchUp(tp->id(), tp->time());
                    }
                );
                connect(m_touch, &Touch::pointMoved, this,
                    [this] (TouchPoint *tp) {
                        m_backend->touchMotion(tp->id(), tp->position(), tp->time());
                    }
                );
            } else {
                destroyTouch();
            }
        }
    );
    WaylandServer *server = waylandServer();
    if (server) {
        using namespace KWayland::Server;
        SeatInterface *si = server->seat();
        connect(m_seat, &Seat::hasKeyboardChanged, si, &SeatInterface::setHasKeyboard);
        connect(m_seat, &Seat::hasPointerChanged, si, &SeatInterface::setHasPointer);
        connect(m_seat, &Seat::hasTouchChanged, si, &SeatInterface::setHasTouch);
        connect(m_seat, &Seat::nameChanged, si, &SeatInterface::setName);
    }
}

WaylandSeat::~WaylandSeat()
{
    destroyPointer();
    destroyKeyboard();
    destroyTouch();
}

void WaylandSeat::destroyPointer()
{
    delete m_pinchGesture;
    m_pinchGesture = nullptr;
    delete m_swipeGesture;
    m_swipeGesture = nullptr;
    delete m_pointer;
    m_pointer = nullptr;
}

void WaylandSeat::destroyKeyboard()
{
    delete m_keyboard;
    m_keyboard = nullptr;
}

void WaylandSeat::destroyTouch()
{
    delete m_touch;
    m_touch = nullptr;
}

void WaylandSeat::installCursorImage(wl_buffer *image, const QSize &size, const QPoint &hotSpot)
{
    if (!m_installCursor) {
        return;
    }
    if (!m_pointer || !m_pointer->isValid()) {
        return;
    }
    if (!m_cursor) {
        m_cursor = m_backend->compositor()->createSurface(this);
    }
    if (!m_cursor || !m_cursor->isValid()) {
        return;
    }
    m_pointer->setCursor(m_cursor, hotSpot);
    m_cursor->attachBuffer(image);
    m_cursor->damage(QRect(QPoint(0,0), size));
    m_cursor->commit(Surface::CommitFlag::None);
    m_backend->flush();
}

void WaylandSeat::installCursorImage(const QImage &image, const QPoint &hotSpot)
{
    if (image.isNull()) {
        installCursorImage(nullptr, QSize(), QPoint());
        return;
    }
    installCursorImage(*(m_backend->shmPool()->createBuffer(image).data()), image.size(), hotSpot);
}

void WaylandSeat::setInstallCursor(bool install)
{
    // TODO: remove, add?
    m_installCursor = install;
}

void WaylandSeat::setupPointerGestures()
{
    if (!m_pointer || !m_gesturesInterface) {
        return;
    }
    if (m_pinchGesture || m_swipeGesture) {
        return;
    }
    m_pinchGesture = m_gesturesInterface->createPinchGesture(m_pointer, this);
    m_swipeGesture = m_gesturesInterface->createSwipeGesture(m_pointer, this);
    connect(m_pinchGesture, &PointerPinchGesture::started, m_backend,
        [this] (quint32 serial, quint32 time) {
            Q_UNUSED(serial);
            m_backend->processPinchGestureBegin(m_pinchGesture->fingerCount(), time);
        }
    );
    connect(m_pinchGesture, &PointerPinchGesture::updated, m_backend,
        [this] (const QSizeF &delta, qreal scale, qreal rotation, quint32 time) {
            m_backend->processPinchGestureUpdate(scale, rotation, delta, time);
        }
    );
    connect(m_pinchGesture, &PointerPinchGesture::ended, m_backend,
        [this] (quint32 serial, quint32 time) {
            Q_UNUSED(serial)
            m_backend->processPinchGestureEnd(time);
        }
    );
    connect(m_pinchGesture, &PointerPinchGesture::cancelled, m_backend,
        [this] (quint32 serial, quint32 time) {
            Q_UNUSED(serial)
            m_backend->processPinchGestureCancelled(time);
        }
    );

    connect(m_swipeGesture, &PointerSwipeGesture::started, m_backend,
        [this] (quint32 serial, quint32 time) {
            Q_UNUSED(serial)
            m_backend->processSwipeGestureBegin(m_swipeGesture->fingerCount(), time);
        }
    );
    connect(m_swipeGesture, &PointerSwipeGesture::updated, m_backend, &Platform::processSwipeGestureUpdate);
    connect(m_swipeGesture, &PointerSwipeGesture::ended, m_backend,
        [this] (quint32 serial, quint32 time) {
            Q_UNUSED(serial)
            m_backend->processSwipeGestureEnd(time);
        }
    );
    connect(m_swipeGesture, &PointerSwipeGesture::cancelled, m_backend,
        [this] (quint32 serial, quint32 time) {
            Q_UNUSED(serial)
            m_backend->processSwipeGestureCancelled(time);
        }
    );
}

WaylandBackend::WaylandBackend(QObject *parent)
    : Platform(parent)
    , m_display(nullptr)
    , m_eventQueue(new EventQueue(this))
    , m_registry(new Registry(this))
    , m_compositor(new KWayland::Client::Compositor(this))
    , m_shell(new Shell(this))
    , m_surface(nullptr)
    , m_shellSurface(NULL)
    , m_seat()
    , m_shm(new ShmPool(this))
    , m_connectionThreadObject(new ConnectionThread(nullptr))
    , m_connectionThread(nullptr)
{
    connect(this, &WaylandBackend::connectionFailed, this, &WaylandBackend::initFailed);
    connect(this, &WaylandBackend::shellSurfaceSizeChanged, this, &WaylandBackend::screenSizeChanged);
}

WaylandBackend::~WaylandBackend()
{
    if (m_pointerConstraints) {
        m_pointerConstraints->release();
    }
    if (m_xdgShellSurface) {
        m_xdgShellSurface->release();
    }
    if (m_shellSurface) {
        m_shellSurface->release();
    }
    if (m_surface) {
        m_surface->release();
    }
    if (m_xdgShell) {
        m_xdgShell->release();
    }
    m_shell->release();
    m_compositor->release();
    m_registry->release();
    m_seat.reset();
    m_shm->release();
    m_eventQueue->release();

    m_connectionThreadObject->deleteLater();
    m_connectionThread->quit();
    m_connectionThread->wait();

    qCDebug(KWIN_WAYLAND_BACKEND) << "Destroyed Wayland display";
}

void WaylandBackend::init()
{
    connect(m_registry, &Registry::compositorAnnounced, this,
        [this](quint32 name) {
            m_compositor->setup(m_registry->bindCompositor(name, 1));
        }
    );
    connect(m_registry, &Registry::shellAnnounced, this,
        [this](quint32 name) {
            m_shell->setup(m_registry->bindShell(name, 1));
        }
    );
    connect(m_registry, &Registry::seatAnnounced, this,
        [this](quint32 name) {
            if (Application::usesLibinput()) {
                return;
            }
            m_seat.reset(new WaylandSeat(m_registry->bindSeat(name, 2), this));
        }
    );
    connect(m_registry, &Registry::shmAnnounced, this,
        [this](quint32 name) {
            m_shm->setup(m_registry->bindShm(name, 1));
        }
    );
    connect(m_registry, &Registry::pointerConstraintsUnstableV1Announced, this,
        [this](quint32 name, quint32 version) {
            if (m_pointerConstraints) {
                return;
            }
            m_pointerConstraints = m_registry->createPointerConstraints(name, version, this);
            updateWindowTitle();
        }
    );
    connect(m_registry, &Registry::interfacesAnnounced, this, &WaylandBackend::createSurface);
    connect(m_registry, &Registry::interfacesAnnounced, this,
        [this] {
            if (!m_seat) {
                return;
            }
            const auto gi = m_registry->interface(Registry::Interface::PointerGesturesUnstableV1);
            if (gi.name == 0) {
                return;
            }
            auto gesturesInterface = m_registry->createPointerGestures(gi.name, gi.version, m_seat.data());
            m_seat->installGesturesInterface(gesturesInterface);
        }
    );
    if (!deviceIdentifier().isEmpty()) {
        m_connectionThreadObject->setSocketName(deviceIdentifier());
    }
    connect(this, &WaylandBackend::cursorChanged, this,
        [this] {
            if (m_seat.isNull() || !m_seat->isInstallCursor()) {
                return;
            }
            m_seat->installCursorImage(softwareCursor(), softwareCursorHotspot());
            markCursorAsRendered();
        }
    );
    initConnection();
}

void WaylandBackend::initConnection()
{
    connect(m_connectionThreadObject, &ConnectionThread::connected, this,
        [this]() {
            // create the event queue for the main gui thread
            m_display = m_connectionThreadObject->display();
            m_eventQueue->setup(m_connectionThreadObject);
            m_registry->setEventQueue(m_eventQueue);
            // setup registry
            m_registry->create(m_display);
            m_registry->setup();
        },
        Qt::QueuedConnection);
    connect(m_connectionThreadObject, &ConnectionThread::connectionDied, this,
        [this]() {
            setReady(false);
            emit systemCompositorDied();
            m_seat.reset();
            m_shm->destroy();
            if (m_xdgShellSurface) {
                m_xdgShellSurface->destroy();
                delete m_xdgShellSurface;
                m_xdgShellSurface = nullptr;
            }
            if (m_shellSurface) {
                m_shellSurface->destroy();
                delete m_shellSurface;
                m_shellSurface = nullptr;
            }
            if (m_surface) {
                m_surface->destroy();
                delete m_surface;
                m_surface = nullptr;
            }
            if (m_shell) {
                m_shell->destroy();
            }
            if (m_xdgShell) {
                m_xdgShell->destroy();
            }
            m_compositor->destroy();
            m_registry->destroy();
            m_eventQueue->destroy();
            if (m_display) {
                m_display = nullptr;
            }
        },
        Qt::QueuedConnection);
    connect(m_connectionThreadObject, &ConnectionThread::failed, this, &WaylandBackend::connectionFailed, Qt::QueuedConnection);

    m_connectionThread = new QThread(this);
    m_connectionThreadObject->moveToThread(m_connectionThread);
    m_connectionThread->start();

    m_connectionThreadObject->initConnection();
}

void WaylandBackend::createSurface()
{
    m_surface = m_compositor->createSurface(this);
    if (!m_surface || !m_surface->isValid()) {
        qCCritical(KWIN_WAYLAND_BACKEND) << "Creating Wayland Surface failed";
        return;
    }
    using namespace KWayland::Client;
    auto iface = m_registry->interface(Registry::Interface::ServerSideDecorationManager);
    if (iface.name != 0) {
        auto manager = m_registry->createServerSideDecorationManager(iface.name, iface.version, this);
        auto decoration = manager->create(m_surface, this);
        connect(decoration, &ServerSideDecoration::modeChanged, this,
            [this, decoration] {
                if (decoration->mode() != ServerSideDecoration::Mode::Server) {
                    decoration->requestMode(ServerSideDecoration::Mode::Server);
                }
            }
        );
    }
    if (m_seat) {
        m_seat->setInstallCursor(true);
    }
    // check for xdg shell
    auto xdgIface = m_registry->interface(Registry::Interface::XdgShellUnstableV6);
    if (xdgIface.name != 0) {
        m_xdgShell = m_registry->createXdgShell(xdgIface.name, xdgIface.version, this);
        if (m_xdgShell && m_xdgShell->isValid()) {
            m_xdgShellSurface = m_xdgShell->createSurface(m_surface, this);
            connect(m_xdgShellSurface, &XdgShellSurface::closeRequested, qApp, &QCoreApplication::quit);
            setupSurface(m_xdgShellSurface);
            return;
        }
    }
    if (m_shell->isValid()) {
        m_shellSurface = m_shell->createSurface(m_surface, this);
        setupSurface(m_shellSurface);
        m_shellSurface->setToplevel();
    }
}

template <class T>
void WaylandBackend::setupSurface(T *surface)
{
    connect(surface, &T::sizeChanged, this, &WaylandBackend::shellSurfaceSizeChanged);
    surface->setSize(initialWindowSize());
    updateWindowTitle();
    setReady(true);
    emit screensQueried();
}

QSize WaylandBackend::shellSurfaceSize() const
{
    if (m_shellSurface) {
        return m_shellSurface->size();
    }
    if (m_xdgShellSurface) {
        return m_xdgShellSurface->size();
    }
    return QSize();
}

Screens *WaylandBackend::createScreens(QObject *parent)
{
    return new BasicScreens(this, parent);
}

OpenGLBackend *WaylandBackend::createOpenGLBackend()
{
#if HAVE_WAYLAND_EGL
    return new EglWaylandBackend(this);
#else
    return nullptr;
#endif
}

QPainterBackend *WaylandBackend::createQPainterBackend()
{
    return new WaylandQPainterBackend(this);
}

void WaylandBackend::flush()
{
    if (m_connectionThreadObject) {
        m_connectionThreadObject->flush();
    }
}

void WaylandBackend::togglePointerConfinement()
{
    if (!m_pointerConstraints) {
        return;
    }
    if (!m_seat) {
        return;
    }
    auto p = m_seat->pointer();
    if (!p) {
        return;
    }
    if (!m_surface) {
        return;
    }
    if (m_pointerConfinement && m_isPointerConfined) {
        delete m_pointerConfinement;
        m_pointerConfinement = nullptr;
        m_isPointerConfined = false;
        updateWindowTitle();
        flush();
        return;
    } else if (m_pointerConfinement) {
        return;
    }
    m_pointerConfinement = m_pointerConstraints->confinePointer(m_surface, p, nullptr, PointerConstraints::LifeTime::Persistent, this);
    connect(m_pointerConfinement, &ConfinedPointer::confined, this,
        [this] {
            m_isPointerConfined = true;
            updateWindowTitle();
        }
    );
    connect(m_pointerConfinement, &ConfinedPointer::unconfined, this,
        [this] {
            m_isPointerConfined = false;
            updateWindowTitle();
        }
    );
    updateWindowTitle();
    flush();
}

void WaylandBackend::updateWindowTitle()
{
    if (!m_xdgShellSurface) {
        return;
    }
    QString grab;
    if (m_isPointerConfined) {
        grab = i18n("Press right control to ungrab pointer");
    } else {
        if (!m_pointerConfinement && m_pointerConstraints) {
            grab = i18n("Press right control key to grab pointer");
        }
    }
    const QString title = i18nc("Title of nested KWin Wayland with Wayland socket identifier as argument",
                                "KDE Wayland Compositor (%1)", waylandServer()->display()->socketName());
    if (grab.isEmpty()) {
        m_xdgShellSurface->setTitle(title);
    } else {
        m_xdgShellSurface->setTitle(title + QStringLiteral(" - ") + grab);
    }
}

QVector<CompositingType> WaylandBackend::supportedCompositors() const
{
#if HAVE_WAYLAND_EGL
    return QVector<CompositingType>{OpenGLCompositing, QPainterCompositing};
#else
    return QVector<CompositingType>{QPainterCompositing};
#endif
}


}

} // KWin